To assist disabled persons in boarding public conveyances such as buses, there have been devised various means for boarding. Of course a present means is to use a folding wheelchair but this manner of boarding requires that the disabled person be able to proceed up the steps and frequently the person cannot walk. In addition, persons walking on crutches or with a cane frequently are unable to maneuver the steps of a public bus. As a result there have been devised various lifts which raise the person to the passenger level in the bus.
Preferably such lifts allow the passenger to board a platform at the sidewalk level and be raised to the passenger level. In addition the less maneuvering the passenger has to effect in boarding and dismounting from the lift the better. Such is true because during such boarding the passenger is subjected to unfamiliar surroundings and moveable mechanisms and as a result, may not be able to maneuver in the best manner, whether on crutches or in a wheelchair.
In addition, it is important that such a lift occupy as little space as possible in the bus because such space is subtracted from the passenger capacity and may not be used most of the time. The weight and complexity of such mechanisms also are important because of economy and maintenance problems. Also not the least of considerations in the use of such lifts, are safety considerations such as safety to the passenger using the lift and also the safety of other passengers in being protected from the lift mechanism and also being guarded against falling into the lift well when the platform is operating or in the lowered position. Of course there are other safety considerations such as locking the mechanism against operation while the bus in in motion and enabling the user to stop the mechanism if trouble arises. In addition, such lifts must be capable of being lowered to different heights and still operate conveniently because sidewalks and curbs are of varying heights relative to the street level.
In the past one lift mechanism used involved a platform which could be raised and lowered but also which folded to a vertical position when in the raised position to permit closing of the vehicle doors. In this type of mechanism the passenger boards the platform at the lowered position, is raised to the passenger level and thereafter must leave the platform before it can be folded upward for storage to allow for closing the doors. When disembarking the passenger must wait in the aisle for the platform to fold down to the horizontal position, board the platform and thereafter be lowered to street level.
One problem which immediately arises in the use of this previously-used lift is the time necessary for boarding and discharging disabled persons. In each instance the disabled passenger had to leave the platform after being raised to the passenger level prior to the platform being folded for closing the doors. When departing the passenger must await the folding down of the platform and then maneuver thereon prior to being lowered to ground level.
Not only does such action take additional time during which the bus must be standing still, but additionally the person disembarking is required to maneuver onto the raised platform while the doors are open. While guard rails can be provided, still there can be a concern on the part of the person for his safety because such maneuvering is required at an elevated position.
In addition while the lift is lowered to the street level position the other passengers must be protected against falling into the well created by the lowered platform. While guard rails can be provided, still these guard rails must be swung out of position when the platform is at passenger level to allow movement of the disabled person onto and from the platform. The maneuvering of such guard devices must always be accomplished without exposing the passengers to additional hazards.
In addition there are times that there is limited side clearance between the conveyance and obstructions at the loading place. For instance with buses, there may be signs, trees, et cetera, near the loading zone which limit the space in which the lift can be operated.
Thus it can be seen that the provision of a platform for lifting disabled persons into a public conveyance such as a bus presents various problems of design, operation and safety. It is the purpose of this invention to provide such a lift which is convenient to use yet is compact, safe and efficient in design.